Zerland



May 10,1927, 1,628,377

H. VOGT ET AL MEANS FOR CONTROLLING AMPLITUDE OF HIGH FREQUENCY OSCILLATIONS Filed April 4, 1921' 2 Sheets-Sheet 1 INVENTORS:

L/OSEPH MqssoLLE H s V007" (J05 EF ENGL flr ro ENE s 1,628,337? May 1927' H. VOGT ET AL MEANS FOR CONTROLLING AMPLITUDE OF HIGH FREQUENCY OSCILLATIONS Filed April 4. 1921 $2 Sheets-$heeic '2 INVENTU R5 L/OSE PH IVassou g Haws V067- o .SEF' ENGL.

Patented May 10, 1927.

UNITE!) time.

HANS voe'r, or BERLIN-scnoNEBDRo, AND Josnr ENG; AND aosnrir MASSOLLE, or GRUNEWALD, GERMANY. ASSIGNORS TO {URI-ERGO}! LIMITED, or ZURICH, SWIT- ZERLAND. y 1

MEANS non CONTROLLING AMPLITUDE or HIGH-FREQUENCY oscrma'rioivs.

Application filed Apri1 4, 1921, Serial No. 458,630," and in Germany Apri1 7, 1919.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. L, 1313.)

must be controlled or acted. upon in the sense of the low frequency oscillations;

The present inventionmakes this possible in such a manner that a source of radiat on controllcdin the sense of the low frequency w acts upon a photoelectric cell having an alkali cathode and thus controls the high frequency amplitude. The light which falls upon the photoelectric cell may he varied in intensity by and in accordance with souud i vibrations, for example. Such cells, such as the potassium cell, are known. They consist of two electrodes. enclosed in a glass tube which is either at a vacuum or filled with rare gas, one of said el-ectrodes being composed of alkaline metal. If an electrical potential is applied between these two electrodes, in such a way that the electrode which is coated with alkaline metal is negative, an irradiation of the cell by light sets 5 up a flow of electrons from the alkaline metal to the positive electrode, this emission being directly proportional to the irradiation. If the sign of the potential be re versed, i. e. ifa positive potential is connected with thealkaline metal electrodes, no How of electrons will ensue. The resistance and the capacity between the electrodes vary according to the electron discharge. 7 If the cell be. connect-ed in the usual manner with an electrical. oscillatory circuit the E. M. F. of which produces the requisite potential for the cell. the variations at the cell effect a control of the amplitude of the pulsating oscillations in the circuit so that the latter are directly, or almost directly, proportional. to the variations in the illumination of the cell. lhe necessary coupling,

between the cell and the oscillating circuit. may be effected directly or by induction or capacity.

In accordance with the invention a photoelectric cell is coupled to an oscillatory circuitas stated. which circuit may be one of a: scrres of coupled. tuned circuits containing inductance and capacity, to, modulate the current flowing therein in accordance with variations of illumination received by the cell. The illumination of the cell may be acoustically-modulated, as stated, or modulated, generally speaking, in accordance with some form of energy varying with a lower frequency than that of the high frequency carrier waves flowing in the said circuit or coupled circuits, so that the current flowing in said circuit or circuits will be corre spondingly modulated. In a further development bf the invention, oscillatory circuits, in which flow current modulated in the manner indicated, may be differentially coupled to another circuit, in which a result ant current Will flow, and in which the modulation effect may be increased. Objects of the invention comprise the provision of arrangements in accordance with the foregoing, and also comprise combinations and arrangements of parts all as will be more fully set forth hereinafter in the following specification and be particularly pointedout in the appended claims.

In order that the invention may be clearly understood, we will proceed to describe the same with reference to the different forms of construction diagrammatically shown in. the accompanying drawings, wherein 1- Figs. 1a and 16 show diagrams of connections betweena photoelectric cell and an oscillation circuit with direct coupling and inductive coupling respectively.

Figs. 2a and 27) are views similar to Figs.

1a and 1?) representing connections of a cell having three electrodes with an oscillation circuit.

Figs. 3 and 4 show different connections in i which coupling of the cell can be effected indirectly.

Figs. 5a and 5b, 6a and 67) and 7 show connections to be used for producing preliminary voltage.

Fig. 8 shows a curve relating to the effect of the cell.

Fig. 9 shows a simple arrangement for coupling the circuits in a special manner.

Fig. 10 is a diagrammatic view of a photo- Lil electric cell having two cathodes and one anode, as a modification of the cell indicated in Figs. 2a and other figures.

Similar reference characters referto similar elements or parts throughout the drawings.

In Figures 1a and it the circuit S in each instaiice'is fedeirceit whicnfed by a genorator with' undainped high frequency en ergy, excites the circuit D from which the energy f n-then transmitted to the circuit K. Circui'ts STDfand 'K are resonant cir cuits, containing inductance and capacity. An input circuit is indicated at I, in circuit S, inductively coupled tocircuit' S, and an output circuit is similarly indicated in circuit K, at O. In the connection according to 1a, direct coupling is used by connect ing the cell Z in parallel with the condenser ott the circuit D, the maximum potential of which is adapted to that of the cell. in the connection according to Fig. 1b, the cell is coupled inductively to the circuit D in such a manner-that the maginium potential necessary for the cell is obtained. In both cases the connection of the'cell to tuned circuit D eiiccts a slight untuning of the same, whereby the current therein,an'd transmitted inductively therefrom to output 'circuit K, is modulated in accordance with the variations of resistance in the cell, which maybe pro- 'duced in accordance with variations of sound-modulated light, or by other variations of radiant energy, as stated.

Iuthese connections the cell, on account oi? its polarity, becomes operative only during each hall period of the oscillationsin circuit D. Bilateral action takes place by the connections as shown by Figs. 2a and 27. in which a cell is provided with three electrodes of which two are of the same polarity (say, positive), one of which becomes operative during each half-period.

In Fig. 2a the cell has two anodes, each connected to circuit D across a capacity, condensers C and C being positioned in circuit D between the connections from the cathode ottthe cell and one anode, andbetween the connections from the cathode and the other anode, respectively. Current flows from one anode during one halt of the cycle oi the alternating current, and from the other anode during the other half. Circuit D is slightly untuned by the varying charging of the condensers, so that both halves of the cycle are utilized and the modulated current flows in circuit D during the com plete cycle. Fig. 2b is the sameexcept that the cell circuits are inductively coupled to circuit F 10 shows a modificd forni of cell in which a single anode is used with a pair oi? cathodes, instead of a single oath ode" and a pair of anodes, as" iaFi iQa. This cell may be substituted for th'"ce' ll shown'in Figs. 2a. 25,3 an'dd, and suitable untune d with respect to the frequen y of circuit S. The damping loss of circuit D is esistance also varied by altering the ohmic of the photo-electric cell. Botlrt'acts; namely untuning and variation of damping, cause variation in the transfer of high frequency energy from circuit S through circuit D to circuit K. By a proper choice of the original damping of circuit D both facts may be utilized either together or one nioret-han the other.

The amplitude variation caused by the va riation of 'il'GqdGDCy will not be great with the connection au'anged as shown in Figs. 2a and 2?). ditlerential connections inwhich the phase displacement between the current and voltage, caused by somewhat untuningfthe oscillating circuit, is made use of.

Figs. 3 and i show such differential cen uections in which the coupling otlthe cell can also be etlected indirectly. In both iiguies, there are provided two circuits D and D which are excited by circuit S and which transmit the energy to circuit K. All the circuits are tuned to the same wave and so inlercoupled that with a non-illun'iinated cell no current flows through the circuit H. In the connection shown in Fig. 3 the circuit D with the cell exposed to'light, is altered in the same way as the circuit D in the connections shown by Fig. 2a, circuit D remaining unaltered. The difference of its amplitudes as comparec with those of D is now transmitted to the circuit K in which.

as the variation of the amplitudes of D occur at each half period, an alternating current of the same frequency is generated.

In the connections shown in Fig.3 the inductances L and L in circuits D and D ailecting circuit K. are wound in the same direction. The feed circuit S has inductances on opposite sides oi the condenser C in circuit S. and accordingly feeds circuits D and D oppositely. Accordingly, L and L being wound in the same direction, circuits D and Dj induce current in opposite directions in circuit current in circuit l: is zero when the cell is not illuminated.

by,'which results in a difilerential eiiect in circuit "K, so that a modulated high frequency current flows in circuit K, which is It can be greatly increased by and the resulting lVhen the cell is illu 1'ninated,circuit D is slightly untuned there- Li I ' ice a. resultant of the effects produced by circuit D and the slightly untuned circuit D .[he, current flowing in circuit ltvaries between-two limits, the upper limit being the current induced by circuit D alone, when no current is induced by circuit D because the latter. has been untuned to a suttic-ient extent. At the other limit circuit D exertsfa certain inductive effect on circuit K, which counteractsto this extent the effect of circuit D on K. The action of the difterential circuits is somewhat similar to that described in our 'c o pendlng application,

vefi'ect on K are displaced by phaseangle of ;180, the current transmitted to Khas always .thesame direction. It. is therefore a pulsating pontinuous current; with the rhythm offthe high frequency half-period,

which can eventually be useddirectly.

' The. connections in Fig. 4 differ from those of F i 3 in thatthe diifercntial circuits D and 2 are connected, one to one anode and the other .to the other anode of cell Z, the cathode of which is connected to circuits iD. and D betweenthe condensers C and C? thereof, the anodes of the cell being connected on, the opposite. sides of the con densers. Accordingly untun'ing, efi'ects are obtained in. circuits D and D .in onejin one half of the cycle, and in the :other in' the otherhalt of the cycle. The inductive couplings of circuits D andD with circuit K are so WOllIlClflS to produceopposite effects andinput circuit S being oppositelyconnected by inductance to circuits D? and D the result is that an undulating direct current is produced in circuit K, the connections described rectifying the current.

For the rest, the current-f produced in all the, various connection schemes can be amplified whereby those produced according to Fig/4 again become alternating currents.v

but of doubletheqfrequency of those, of the circuit'D. y.

In case of amplification, the differential connections as shown by Figs. 3 and 4 have the advantage overthe simple arrangements shown by Figs. 1a and 2a that. thecurrent to be amplified pulsates from zero up to a maximum which permits a better utilization of the amplifier device. N

The efiect o t' the cell sensitive to irradiation is not proportional to the voltage applied. I It starts practically only at a certain definite voltage and then rises in a steep curve until at a given voltage, glow discharge sets in (Fig. 8).

effectof'the cell in conjunction with an os cillatory circuit is thereby considerably di.

The controlling niinished as the phase is only intensively utilizedi'rom a tairlyhigh tensiononwards. By means ot'a suitably selected tlll'QCt current preliminary voltage this can beavoided.

The alternating voltage Ff, which practically can attain to the flashing po1nt Z,

comes thereby'within the rangeoi? the steep curve. In the Figs. 5a. 5b, 6a, 00 and" 7 posslble connections for providing the preliminary voltage are shown.

will then differ from circuits 1a,-lbe and 2a only in that the direct current source is included in circuit with cellZ in each a Fig. 66 may be made complete by theaddition of circuits S, D and K, as shown in Fig. 2?). Fig. 7 corresponds to Fig. 4t, with the inclusion of the direct current source in circuit with the cell, and maybe com-' pleted by the addition of circuits S and K of Fig. 4. In allot them the current output of the cell is improved as shown bythe cur-. rent-voltage characteristic of the cell shown in Fig. 8, in which E is the constant direct voltage and E is the alternating current voltagertransmitted to circuit Da,Db, Dc,

etc. The current in "Fig. 8 is represented by the vertical co-ordinate c y In order to obtain the most favourable conditions with the differential connections the-circuitK must not be directly coupled with circuit S. S must supply its energy only to D and to D which whenever possible must also havev no coupling with each other, and with which IQ is so coupled that the currentsin D and D compensate each otherso long as the cell is not irradiated.

Only when by the irradiationof the cell the balance or static condition between D and D is disturbed, the measure of this dis turbance is. transmitted'to K. A sim )le arrangement for producing these conditions .of coupling is that shown by'Fi 9 in which the requisite tour coils are arrangedin one field. D and D are perpeinlicular toone one another, as are also S and K. S and K are then so turned with regard toD and D that in K the desired effect is produced.

I That is to say, there will be no :material. inductance ettects'between S and K, and beon I tween D and D, but coupling between the coils which are at angles of 45 from each other will exist, so that circuit S will nduce V currents n c1rcmts..D and D .-and circuits Di and D? will. induce currentsin circuitK,

use

'plicatiou Serial No; i-51137 referred to above, which may beconunon to both, in re gard' to dil'l'ercntial circuits, 'claimscovering such common subject matter will be made a photoelectric cell andf neans'tor coupling said-cell to'said circuit by one of said tuning factors to var-y. the "inductance-capacity l t t i t -tl b l piocuc r6190 a. 1eie y somew iat un tune thc'same in accordance with variat ons oi light received by said-cell. 2. In electric-oscillation controlling de vices, the combination ot' ai plurality tot tuned circuits containin caoacitv and 1n- 7 r1 1. v duct'ance, coupled togctheiz n s for sup; plying high frequency oscillations to one of said circuitsyaphotoelectr c cell, and means for COU)l1D "S2UCl cell to another one" o t sa l Z3 1 circuits to vary the" nductancccapac ty product thereof, to somewhat untune the same and thereby cause modulation of tho current in said circuit in accordance'wit'h vai'f-iatioiis of light received by said cell.

3. In e'lectric-oscillation controll' devices, the combination of a tunedhi quency oscillatory circuit containinginductance and capac" y. means for setting up high frequency oscill tions in said circuit, a

photoelectric cell having" an anode' 'ande 1 cathode. and means for socoupling' said cell to said circuit 3 as to provide from' the E. M. F. of said circuit, a difference ofpotential betweenthe electrodes of said cell, with the cathode negative with respect to the anode to vary the inductance-capacity prod not of said circuit, to somewhatuntune the same, and thereby cause inodulationcf th v current in said circuit in accordance with variations of light received said'cell.v

4-. In electric oscillatio'n controlling devices. the combination of a high frequency oscillatory" circuit containing inductance and capacity, means for setting up high tre quency oscillations in said circuit, a photoelectric cell having: an anode and a cathode, and means .tor connecting said anode 19 d cathode across capacity said circuit to vary the ind ictance-capacity product of said. circuit. to somewhat untuno the same. and thereby cause modulation ot the current in said circuit in accordance with variations of light received by said cell. v

5. In electric-oscillation controlling devices, the combination of a tuned high frequency oscillatory circuit containing inductance and capacity, means for setting up high frequency oscillations'in said circuit, a photoelectric cellv having one electrode of one (t free polarity and two electrodes of opposite" polarity, til?'Ifi(l1lCtftT1 iGtl11l capacity ot said circuit constituting the tuningilactors there l, andnieans' for so coupling said electrodes by one oi? said tuning factors to said circuit as to'va'ry the inductancccapa 'ity product of said circuit, to somewhat uutune the same, r id thereby cause modulation of the current in kid circuit urine the whole cycle of the high frequencyalternating current in accordance with variations of light received by said cell;

- 6. In electric-oscillation controlling :devices, the combination of a resonant'high frequency oscill'atory circuit containing in ductane and a pair of condensers, means for setting, up oscillations in" said circuit, a photoelectric cell having a cathode and a pair of anodes, and means for connecting I .thejcathode and one anodeacross one'ot said condensers and the. cathode and the other anode across the other one of said condensers tocause modulation'ot the current in said circuit in accordance witl'i variations of light received by said cell 7 7. In electric-oscillation controlling dedevices, the combination ofa pair of cir the diiierential effect of said first't-wo circuits on said third circuit.

8. In electric-oscillation controlling devices, the combination of a. pair of circuits, containing similar'inductance and capacity, means for supplying alternating current equally thereto, the 'capacity-inductance products of said circuits being so adjusted" that currents flowing therein will have a desired normal phase relation to eachother, a third circuit so coupled with said first two circuits as to have a resultant current produced therein, a photoeletric cell, having a cathode-and apair oit'anodes. the inductance and capacity of said first two circuits con stituting' "the tuning factors thereof. and means for so coupling the electrodes otsaid cell to said first two circuits, by one of the tuning factorsv of each, as to cause 1nodula tionof the current flowing inone of said first two circuits during one half of the cycle of the alternating current, and modulation of the currentflowing in the other of said first two circuits, during the other half of the cycle, to modify correspondingly the current produced in said third circuit, in accordancc with variations of light received by said cell. V

9. In electric-oscillation controlling devices, the combination of a feed circuit, a pair of circuits coupled therewith to besupplied equally with alternating current thereby, all of said circuits containing similar in ductancc and capacity, a fourth circuit differentially coupled to said pair of circuits to receive a resultant current therefrom, and means for variably untunlng one of said pair of circuits to correspondingly alter the current produced in said fourth circuit, the inductance coils of said feed and fourth circuits being at right angles and the inductance coils of said pair 0i. circuits being at right angles to each other. i

In testimony whereof We afiix our signaturcs.

HANS VOGT. DR. J OSEF ENGL. JOSEPH MASSOLLE. 

